diff --git a/public_html/script.js b/public_html/script.js
index 57c4d96..795c750 100644
--- a/public_html/script.js
+++ b/public_html/script.js
@@ -1457,7 +1457,7 @@ function initializeUnitsSelector() {
 }
 
 function onDisplayUnitsChanged(e) {
-    var displayUnits = event.target.value;
+    var displayUnits = e.target.value;
     // Save display units to local storage
     localStorage['displayUnits'] = displayUnits;
     DisplayUnits = displayUnits;